package com.example.xiongan_app_yy.utils;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Build;
import android.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * Created by wuhang on 2019/5/5.
 */
public class AESUtil {



    @TargetApi(Build.VERSION_CODES.FROYO)
    public static String encryptAES(String data, String key, String iv) throws Exception {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            int blockSize = cipher.getBlockSize();
            byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;

            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);

            return new String(Base64.encode(encrypted, Base64.NO_WRAP));

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * @author miracle.qu
     * @see
     * @param data 密文
     * @param key 密钥，长度16
     * @param iv 偏移量，长度16
     * @return 明文
     */
    @TargetApi(Build.VERSION_CODES.FROYO)
    public static String decryptAES(String data, String key, String iv) throws Exception {
        try
        {
            byte[] encrypted1 = Base64.decode(data,Base64.NO_WRAP);

            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original);
            return originalString.trim();
        }
        catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }


}
